Grinding-mill.



F. D. GIDDINGS.

GRINDING MILL.

WITNESSES:

APPLIGTION FILED MAR. 28, 1914.

OOOOOQOOOOOO OO0.000000000 00000000 O0 000 Patented Mar. 9, 1915.

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THE NORRIS PETERS c0v PHoro-LITHQ. \VASHINGIDN, D

F. D. GIDDINGS.

GRINDING MILL.

APPLICATION FILED MAR.28,1914.

1 13mm, Patented M219, 1915.

3 SHEETS*SHBET 2.

INVENTOR.

WITNESSES.-

FD. G/DDINGS.

ATTORNEY.

rur NORRIS PETFRS CO PHOTO LITHO, WASHINUIDN, D c

P. D. GIDDINGS.

GRINDING MILL.

APPLIGATION FILED MAR. 28, 1914.

Patented Mar. 9, 1915.

3 SHEETS-SHEET 3 WITNES'SES: 4 f w 57 INVENTOR. F0. G/DD/IVGS.

lUFllfTE Tdlfid FRANK I). GIDDINGS, F FORT COLLINS, COLORADO.

GRINDING-MILL.

Specification of Letters Patent.

Application filed March 28, 1914:. Serial No. 827,955.

To all whom it may concern:

Be it known that I, FRANK D. GIDDINGs, a citizen of the United States,residing at Fort Collins, in the county of Larimer and State ofColorado, have invented certain new and useful Improvements inGrinding-Mills, of which the following is a specification.

My invention relates to improvements in grinding mills and moreparticularly in mills designed for grinding alfalfa and other similarproducts, to a meal suitable for animal fodder.

in accordance with my invention 1 provide a stationary concave intowhich the material to be ground is fed by suitable feeding mechanismwhich has been made the subject of a separate application for patent,and in which a grinding cylinder of the character shown and described inmy ap* plication for Patent No. 733,846, has a rotary movement.

The object of the present invention resides more particularly in theconstruction of the concave, which includes simple means for coactionwith the rotary element, to grind the hay, a perforated wall section forthe discharge of the ground product into a suitable receiver, andcooperative devices for preventing breakage and injury of the operativeparts of the grinding element by rocks, nuts, bolts or other obstructiveobjects fed into the concave with the hay, and for the discharge of thesaid objects from the concave during and by the operation of the mill.

In the accompanying drawings in the various views of which like partsare similarly designated, Figure 1 represents a fragmentary plan view ofthe end of the mill at which the grinding element is located, Fig. 2, asection taken along the line 22, Fig. 1, Fig. 3, a transverse sectionalong the line 3-3, Fig. 2, Fig. 1, a section along the line 4-4, Fig.2, Fig. 5, a section taken along the line 5-5, Fig. 2, Fig. 6, a sectionalong the line 66, Fig. 2, Fig. 7, a section along the line 77, Fig. 2,and Fig. 8, a section taken along the line 8-8, Fig. 2.

In the drawings, the numeral 2 designates the forward part of thesupporting frame of the mill on which all its elements are mounted forcooperation.

3 designates the concave which is disposed in the upper portion of acasing 4 provided to receive the ground product discharged through theperforated section of the concave wall, 5 the grinding cylinder whichhas a rotary movement within the concave, and 6 and 7 cooperativemembers of the mechanism by which the material to be ground is fed intothe mouth of the concave, and which has been made the subject of aseparate application for patent, filed simultaneously with the presentone.

The grinding cylinder is composed of a series of adjoining sections 8which are mounted upon a shaft 9 and held in place thereon by a featherl0 and by nuts 12 which are screwed onto the ends of the shaft in,

engagement with the outer sections. Each of the cylinder sections has aseries of equidistant, radially extending wings 18 reinforced by ribsand provided with holes to receive the shanks of bolts 14 by means ofwhich the cutter bars 15 are rigidly and reversibly secured thereto.These bars which in length are equal to the width of the cylindersections, have in their longitudinal edges, teeth of truncated, V-shapedformseparated by spaces of like shape and proportions, and their loweredges are disposed in recesses formed at the feet of the respectivewings as shown at 16 in Fig. 2.

The shaft of the cylinder is rotatably supported in boxes 17 which aresecured upon the angle-shaped side bars 18 of the supporting frame andwhich at their inner ends are provided with webs 19 extending adjacentthe inner surfaces of the said side bars 1 which the ground meal passesinto the casing 1 as will hereinafter be more fully described. Theconcave wall has at one of its sides a space 23 which provides a mouthor feed opening through which the material to be ground is fed by thefeeding appliances here 7 inbefore referred to. The section of the welladjacent the upper edge of this feed opening is composed of a number ofside to side adjoining hinged covers 24 which at their ends remote fromthe edge of the mouth, rest upon a sliding plate 25 which bridges thegap between the said ends and Patented Mar. 9, 1915.. j

the adjacent edge of the perforated section of the concave wall.

The perforated section of the concave wall is composed of two plateswhich are detachably secured upon shoulders formed concentrically on thetwo heads, as best shown in Figs. 7 and 8.

The plates are reenforced by segmental straps 26 fastened along theircurved edges and by rods 27 secured between the said straps. The upperplate of the perforated Wall section is held in place upon the shoulders28 of the heads, by set screws 29 which engage. the straps 26 of theplates and extend through threaded opening in segmental bars 30 whichare hinged to the heads as at 31 and are rigidly secured to the same bymeans of bolts 32. The shoulders upon which the lower plate of theperforated wall section is supported, are formed by arcuate grooves 33cut in segmental enlargements of the heads 20 and the said plate is heldin place by set screws 34: which project through threaded openings inthe said enlargement, into the grooves to engage the straps 26 whichreinforce the plate along its curved edges. To remove the upper part ofthe perforated section for repairs or renewal, the bolts 32 are removedand the bars 30 turned about their hinges 31, and after the upper platehas thus been separated from the heads, the other plate may be readilyremoved by loosening the set screws 34 and then sliding it out of thegrooves 33 into the place formerly occupied by the upper plate.

The series of covers which conjointly provide the portion ofthe concavewall adjacent the upper edge of its month, are each composed of anangular plate, the interior surface of which is partially curved inconformity with the circumference of the concave, and partiallyflattened for the application of a toothed bar 35. The plate hasexteri'orly along its longitudinal edges, curved flanges 36 whichterminate at their rearward ends in knuckles 37 and are at a pointforward of the same, connected by means of a curved transverse rib 38.The covers are hinged on a support 39 by means of a pintle rod 40 whichextends through alined bores in the knuckles of the covers andcorrespondingly formed knuckles 41 on the support 39. The support 39which is secured transversely of the supporting frame, upon thelongitudinally extending side members 18 of the same, forms the upper-edge of the mouth of the concave and its lower edge remote from thelatter engages the roller 6 which is part of the appliance by whichmaterial is fed into the concave in the operation of the machine. Themouth of the concaveis closed at its lower edge by an apron 42 made ofcanvas or other flexible material, which along one of its edges isfastened to a transverse bar l3 at the edge of the feed opening againstwhich the lower perforated plate of the concave wall abuts, while itsopposite edge is held on a plate 4% which is secured to a suitable partof the machine and engages the surface of the endless conveyor belt 7which carries the hay to be ground to the mouth of the concave. Theapron 4-2 provides a bag for receiving rocks or other obstructiveobjects ejected from the concave, as will hereinafter be more fullyexplained.

The covers 24 are provided upon the inner surfaces of their curvedportions with transverse angle bars 45 which are detachably secured bymeans of bolts 46 and which in the outer edges of their inwardlyprojecting parts, are serrated in conformity with the teeth of thecutter bars on the grinding cylinder which during the latters rotarymovement, pass through the interdental spaces of the bars for grindingthe hay. The inwardly projecting edges of the bars 35 which ashereinbefore explained are secured upon the inner surfaces of theflattened portions of the covers are serrated similarly to the anglebars 4-5 and positioned for the passage of the teeth on the cutter barsof the rotary cylinder through their interdental spaces. The anglebetween the two parts of the inner surfaces of the covers is such thatwhen the latter are in their normal position the toothed bars 35 securedagainst their lower flattened parts, will extend into the concaveslantingly with relation to the direction of rotation of the grindingcylinder, thereby causing the cutter bars on the latter to pass them atan obtuse angle, a feature which is of considerable value in theoperation of the machine, as will hereinafter be described. The edges ofthe covers remote from their ends at which they are hinged upon thesupport 39, are reduced in thickness to provide lips e7 which normallyrest upon the before-mentioned plate 25 which is slidingly supported atits ends in grooves 4 8 formed slantingly in the inner surfaces of theheads 20 of the concave. The grooves extend from the peripheral edges ofthe heads slantingly inwardly in substantial tangential relation to thewall of the concave of which. the assembled covers form part, so that arock or other solid object moved through the concave by the rotarymotion of the grinding cylinder, will, when it engages the lower edge orother inwardly projecting portion of the plate 25, move the sameoutwardly in the grooves in which it is supported and thus preventpossible breakage or injury of the mill parts. The covers 2% arenormally held against outward movement about their common, pivotal axis,by means of springs 4L9 which engage blocks 50 secured upon the outersurface of the plate 25 by means of bolts 51. These springs which asshown in Fig. 1 of the drawings, are substantially of U-shaped form, aresecured upon the covers by means of bolts 52, with their normallyparallel, laterally flexible members 53 projecting beyond the lips 47 ofthe same.

The blocks 50 on the plate 25 have at opposite sides, upwardly slopingshoulders, as best shown inFig. 6, which when the parts are in theirnormal position are engaged by thev ends of the spring members 53 andthus retain the covers against outward movement when they are subjectedto the ordinary pressure of the material passing through the concave inthe operation of the mill. An angle bar 54; secured at the outer edge ofthe plate 25 engages with an outwardly turned bar at the adjacent end ofthe perforated section of the concave wall. The concave is as mentionedhereinbefore, partially disposed in a casing at which incloses theperforated section of its wall, to receive the ground meal dischargedthrough the same in the operation of the machine. This casing whichextends to the base of the supporting structure has at one of its ends,inlets 55 for air and at a point opposite thereto, an outlet 56 which inpractice is connected with a suction fan or other similar device fordrawing the contents of the casing to a sacking appliance or to asuitable depository. The upper part of the casing is made separate fromthe lower or body portion of the same and hinged as at 57 to affordaccess to the wall of the concave when it is desired to clean, remove orreplace the perforated plates which form part thereof.

In the operation of the mill the cylinder 5 is rotated by means of abelt 58 shown in Fig. 2, which passes around a pulley mounted on thecylinder shaft, and the movement of the rotary grinding element istransmitted to the feeding mechanism of the machine, by means which donot form part of the present invention and have therefore been omittedfrom the drawings. The hay which in the operation of the machine iscontinuously fed into the mouth of the con cave, is engaged by theradially extending cutter bars 15 on the rotating cylinder and impelledupwardly into the annular space between the said cylinder and thecircumferential wall of the concave. While passing between the teeth onthe rotary element and those of the bars 35 and 45 secured to theportion of the concave wall provided by the assembled covers, and whilemoving along the inner surface of the perforated section of the saidwall, the hay is ground until it is reduced to a fineness which willpermit it to pass through the perforated plates, into the casing 4 fromwhich it is removed by suction as hereinbefore described. A rock, nut,bolt or other obstructive object accidentally fed into the concave withthe hay, will first of all, if of sufficient size, engage one or more ofthe bars 35 at the lower ends of the covers. By reason of the slantingposition of these bars with relation to the radially extendingcutterbars on the cylinder, they present no positive obstruction to thesolid object, but they will, in case the object is of small proportions,compel it to move into one of the spaces between the cutter-bars of thecylinder, to be moved with the same until by centrifugal force it isejected through the mouth of the concave into the bag 42, or, in casethe object is of large dimensions it will on being impelled by thecutter bars against the slanting lower surface of the bars 35, by movingupwardly along the same, gradually compel the covers to open byreleasing their laterally deflective springs from engagement with theshoulders of the respective blocks 50 on the plate 25. The opened coversprovide an opening through which the object can be discharged from theconcave without having injured the operative parts of the mill, or inthe event of the object not passing through the outlet thus provided,they will prevent damage to the cutter bars and other parts of the milluntil the object is ejected through the mouth of the concave and fallsin the bag 42 from which it is afterward removed. Should the obstructiveobject after having passed the covers be projected against the plate 25,it will by engagement with the lower edge or other inwardly projectingpart thereof, move the same outwardly through the grooves 48 in which itis slidingly supported. It will thus be observed that the danger of themill being rendered inoperative by the passage of obstructive objectsinto the concave, as is a common occurrence in the operation of machinesof this character, has

been reduced to a minimum and that in consequence the mill can beoperated for a long period without requiring any attention other thanthat which can be given by any person without special mechanical skill.

Having thus described my invention what I claim and desire to secure byLetters- Patent is:

1. In a grinding mill, a concave the peripheral wall of which includes ahinged outwardly movable, yieldingly-held section, and a rotary grindingelement in said concave, the said section having an inwardly projecting,toothed bar, a surface of which slants in the direction of rotation ofthe said element, and the said element having teeth passing throughthose on the said bar, the said bar being disposed on the section withrelation to the hinge of the same, to cause the section to open byoutward pressure on its said slanting surface.

2. In a grinding mill, a concave the peripheral wall of which includes asection composed of'a series of independently outwardly movable,yieldingly held covers, and a rotary grinding element in said concave,the said covers having inwardly projecting, alined, toothed bars theexterior surfaces of which slant in the direction of rotation of thesaid element, and the said element having teeth passing through those onthe said bar.

3. In a grinding mill, a concave having in its peripheral wall, afeed-opening adj acent an edge thereof, an outwardly movable sectioncomposed of a series of hinged, yieldingly held. covers, and a rotaryelement in said concave, said covers having their ends at the said edgeof the feed-opening and at their said ends alined, toothed members projecting into the concave slantingly in the direction of rotation of therotary element, and the said element having teeth passing between thoseon said members.

4. In a grinding mill, a concave having in 7 its peripheral Wall, afeedopening, adjacent an edge thereof, an outwardly movable sectioncomposed of a series of hinged, yieldingly held covers, and a rotaryelement having outwardly projecting cutter bars, in said concave, thesaid covers having their ends, at the said edge of the feed opening, andat their said ends alined members which project into the concave, andthe lower surfaces of which slant in the direction of rotation of saidelement.

In a grinding mill, a concave including an outwardly movable,yieldingly-held section, and a rotary grinding element in said concave,having outwardly projecting cutter bars, the said section having at itsend forward with relation to the direction of rotation of said element amember projecting into said concave with its lower surface extendingslantingly in the said direction.

6. In a grinding mill, a concave including a section composed of aseries of transversely alined, separately, outwardly movable andyieldingly-held covers and a rotary grinding element having outwardlyprojecting cutterbars in said concave, the said covers having attheirends forward with relation to the direction of rotation of saidelement alined members projecting into said concave with their lowersurfaces extending slantingly in the said direction.

7. In a grinding mill, a concave the peripheral wall of which includes ahinged, outwardly movable section, and a member which provides a supportfor the end of said section remote from its hinge, a laterallydeflective spring on said section, and a block on said member having aseat for the en gagement of said spring to yieldingly hold the sectionagainst outward movement.

8. In a grinding mill, a concave the peripheral wall, ofv which includesa section composed of a series of hinged, outwardly movable covers, anda member providing a support for the ends of said covers remote fromtheir hinge, and codperative means on said covers and said member forholding the covers yieldingly against outward movement.

9. In a grinding mill, a concave the peripheral wall of which includes ahinged, outwardly movable section, and an outwardly slidable memberwhich provides a support for the end of the said section remote from itshinge, and coiiperative means on said member and said section, to yieldingly hold the latter against outward movement.

10. In a grinding mill, a concave the peripheral wall of which includesa section composed of a series of hinged, outwardly movable covers, anoutwardly slidable memher which provides a support for the ends of saidcovers remote from their hinge, and coiiperative means on said memberand said covers to hold them separately, yieldingly against outwardmovement.

11. In a grinding mill, a concave the pe ripheral wall of which includesan outwardly movable, yieldingly-held section, and a rotary grindingelement in said concave, the said section having a plurality of radiallyinwardly projecting toothed cutter-bars, and an inwardly projectingtoothed cutter bar, the exterior surface of which slants in thedirection of rotation of said element, and the said element having teethpassing through those on the said cutter-bars.

12. In a grinding mill, a concave the peripheral wall. of which includesa section composed of a series of outwardly movable, yieldingly-heldcovers, and a rotary grinding element in said concave, the said covershaving each a plu ality of radially inwardly projecting toothed cutterbars, and an inwardly projecting toothed cutter bar, the exteriorsurface of which slants in the direction of rotation of said element,and the said element having teeth passing through those on the saidcutter bars.

13. In a grinding mill, a concave the peripheral wall of which has afeed-opening and includes adjacent said opening, an outwardly movable,yieldingly held section provided with inwardly extending toothed bars,and a rotary grinding element having teeth which pass between those ofthe said bars, the interior surface of the section including tworelatively angularly formed portions one of which forms part of thecylindrical working face of the concave and the other one of whichextends outwardly therefrom at the edge of the said opening, whereby abar secured upon the last-mentioned portion extends slantingly in thedirection of rotationof theelement.

14. In a grinding mill, a concave the peripheral wall of which has afeed opening and includes adjacent said opening a section composed of aseries of hinged, separately outwardly movable and yieldingly heldcovers provided with inwardly extending toothed bars, the interiorsurface of the said section including two relatively angularly formedportions one of which forms part of the cylindrical working face of theconcave and the other one of which extends out wardly at the edge ofsaid opening whereby bars secured upon the last-mentioned portion,extend slantingly in the direction of rotation of the said element.

15. In a grinding mill, a concave having a feed-opening, and a grindingelement having a rotary movement within the same, the said concaveincluding a hinged, outwardly movable section disposed adjacent its saidfeed-opening, and spaced from another portion of the concave, and amember which bridges said space and is slidably mounted for outwardmovement, with its inner portion disposed to be impellently engaged byobjects projected outwardly by action of said element.

16. In a grinding mill, a concave having a feed-opening, and a grindingelement hav ing a rotary movement within the same, the said concaveincluding a hinged, outwardly movable section disposed adjacent its saidfeed opening, and spaced from another portion of the concave, and amember bridging said space and supporting the end of the sectionopposite to that at which it is hinged, the said member being slidablydisposed for outward movement.

17. In a grinding mill, a concave having a feed-opening, and a grindingelement having a rotary movement within the same, the said concave beingcomposed of coaxial heads and a peripheral wall which includes a hingedoutwardly movable section adjacent the said feed-opening and spaced fromanother section of the wall, and a member slidably mounted for outwardmovement in slanting grooves on said heads and supporting the end ofsaid movable section opposite to that at which it is hinged.

18. In a grinding mill, a concave having a feed-opening and an opensection for the discharge of ground material, and a rotary grindingelement in the concave, the concave having between its said opening andits said discharge section, a movable section held yieldingly againstoutward movement and provided with an inwardly extending toothed cutterbar, and the grinding element having teeth passing between those on thebar.

19. In a grinding mill, a concave having a feed-opening and an opensection for the discharge of ground material, and a rotary grindingelement in the concave, the concave having between its said openingand-its said discharge section, a section capable of being movedoutwardly by pressure of matter passing through the concave, andprovided at its edge forward with relation to the direction of rotationof the element, with a toothed bar which projects into the concaveslantingly in the direction of rotation of the element, and the saidelement having teeth passing between those of the bar.

20. In a grinding mill, a concave having a feed-opening and an opensection for the discharge of ground material, and a rotary element inthe concave having longitudinally extending, outwardly projectingcutter-bars, the said concave including between its said opening and itssaid discharge-section, a hinged, yieldingly held section provided witha longitudinally disposed member which projects into the concave freefrom engagement with said cutter-bars and the lower surface of whichslants in the direction of rotation of said element.

In testimony whereof I have affixed my signature in presence of twowitnesses.

FRANK D. GIDDINGS.

Witnesses L. RHoAnns, Gr. J. ROLLANDET.

flopiea of this patent may be obtained for five cents each, byaddressing the Commissioner of Batents- Washington, D. G.

